CrashPlanPROe**: Use CASS as a backup server for your local desktops and servers.

Resiliency

It is important to understand that CASS itself is not backed up. CASS is most often used for storing reproducible data or data that is stored elsewhere, i.e. a backup of a backup. CASS however, at its core, is designed to be resilient to failure. That being said, there are ways that users can configure their storage to enable additional storage resiliency. Below are descriptions of the three options available to all CASS users for configuring their storage.

Basic: This is the default option which relies on the underlying CASS hardware. Data is striped over hardware RAID6 arrays. If CASS ever lost a RAID6 array that some of your data is stored on that data would be lost. With this option, you have all purchased storage available to you – 1TB purchased = 1TB usable. (the space used for the RAID6 parity is included in the base cost of CASS)

Parity: Parity is enabled across the hardware RAID6 arrays. Here, CASS could lose any single RAID6 array we have striped your data over and no data would be lost. This option reserves 12.5% of your purchased space for storing this additional parity and, again, the data is striped over hardware RAID6, parity over parity. 1TB purchased = 875GB usable. This is our most popular resiliency option.

Mirroring: Data is mirrored across two data centers on the UCLA campus. All data written to CASS is synchronously written to two locations. This option uses 50% of your total purchased space (another way to think of this is…you need to buy double). This is the safest option. Here CASS would have to lose two corresponding RAID6 arrays that make up a mirrored pair. 1TB purchased = 500GB usable. This option is best for data you cannot lose and/or is not (easily) reproducible.

* OSX does not natively include an iSCSI initiator (client) which would have to be purchased separately.
** This service requires separate licenses from Code42 to use. Please contact us for more details.

For more information about CASS, contact IDRE Technology Director Bill Labate at labate@ucla.edu.